Multi-band operation for wireless lan systems

ABSTRACT

Systems, methods, and instrumentalities are provided to implement transmission scheduling. A multiband device may send a request via a first frequency band. The request may include a multiband Request to Send (MRTS) transmission. The request may be associated with a second frequency band and/or a beamforming training schedule. The first frequency band may be associated with a quasi-omni transmission and the second frequency band may be associated with a directional transmission. The first frequency band may be a 5 GHz band and the second frequency band may be a 60 GHz band. The multiband device may receive a multiband Clear to Send (MCTS) transmission via the first frequency band confirming the request. The multiband device may be configured to send a beamforming signal in accordance with the request, for example, via the second frequency band. The beamforming signal may be sent in accordance with a beamforming training schedule.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/788,556, filed Mar. 15, 2013, the contents of whichare hereby incorporated by reference herein.

BACKGROUND

With increasing demand for higher bandwidths in wireless local areanetworks (WLANs), advances in WLAN may support devices with multiplefrequency channels, channel bandwidths, etc. Devices with multiplewireless frequency bands may provide different but complementarycharacteristics in terms of coverage range and throughput. However,existing multi-band operation techniques may be inefficient.

SUMMARY

Systems, methods, and instrumentalities are provided to implementtransmission scheduling. A multiband device may send a request via afirst frequency band. The request may be associated with a secondfrequency band. The request may include a multiband Request to Send(MRTS) transmission. The request may be for a transmit opportunity(TxOP) reservation for the second frequency band. The request (e.g., theMRTS) may be associated with a beamforming schedule (e.g., a beamformingtraining schedule and/or a beamforming transmission schedule). The firstfrequency band may be associated with an omni transmission (e.g., aquasi-omni transmission) and the second frequency band may be associatedwith a directional transmission (e.g., a beamformed transmission). Thefirst frequency band may be a 5 GHz band and the second frequency bandmay be a 60 GHz band.

The multiband device may receive a multiband Clear to Send (MCTS)transmission via the first frequency band. The MCTS may indicateacceptance of the request. The MCTS transmission may include a fieldthat indicates whether the request (e.g., a request for a TxOPreservation, a request to send a beamforming transmission, such as abeamforming training transmission or other beamforming transmission,and/or the like) is confirmed. The MRTS and/or MCTS transmissions mayinclude one or more of the following: a schedule field, a multibandcontrol field, a band identification (ID) field, a channel ID field, aband service set identification (BSSID) field, a station media accesscontrol (MAC) address field, and/or the like.

The multiband device may send a beamforming signal in accordance withthe request (e.g., the TxOP reservation). The beamforming signal may bea beamforming training signal, a beamforming transmission signal, and/orthe like. The beamforming signal may be transmitted via the secondfrequency band. The beamforming signal may be part of a sequence ofbeamforming signals. The multiband device may be configured to transmitthe beamforming signal to a region associated with a device that sentthe MCTS transmission.

The multiband device may receive a beamforming schedule (e.g., abeamforming training schedule and/or a beamforming transmissionschedule). The beamforming schedule may be received via an Access Point(AP). The multiband device may be configured to transmit one or moreSector Sweep (SSW) frames via the second frequency band. The one or moreSSW frames may be part of the beamforming schedule. A SSW frame (e.g.,or more) of the one or more SSW frames may not include a MAC body. A SSWframe may include information relating to one or more antenna sectors(e.g., the best antenna sectors) for the beamforming schedule.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an example of a channel coordination mechanism.

FIG. 2 is a diagram of an example of omni range transmission.

FIG. 3 is a diagram of an example reference model for transparentmultiband operation.

FIG. 4 is a diagram of example path loss models that may be used in oneor more WiFi channels.

FIG. 5 is a diagram of an example modulation and coding scheme (MCS)controlled and/or power controlled request to send/clear to send(RTS/CTS) transmission on a 5 GHz band to protect the beamforming and/orbeamforming training transmissions on a 60 GHz band.

FIG. 6 is a diagram of an example multi-band request to send/multi-bandclear to send (MRTS/MCTS) protected directional training and/ortransmission.

FIG. 7 is a diagram of an example use of MRTS/MCTS frames on a 5 GHzband to schedule transmissions on a 60 GHz band.

FIG. 8 is a diagram of an example dedicated MTRS/MCTS for a 60 GHzsector level sweep training.

FIG. 9A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented.

FIG. 9B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 9A.

FIG. 9C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 9A.

FIG. 9D is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 9A.

FIG. 9E is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 9A.

DETAILED DESCRIPTION

A detailed description of illustrative embodiments will now be describedwith reference to the various figures. Although this descriptionprovides a detailed example of possible implementations, it should benoted that the details are intended to be exemplary and in no way limitthe scope of the application.

A WLAN in infrastructure basic service set (BSS) mode may include anaccess point (AP) for the basic service set (BSS) and one or morestations (STAs) associated with the AP. The AP may include an accessand/or an interface to a Distribution System (DS). The AP may include atype of wired/wireless network that may carry traffic in and/or out ofthe BSS. Traffic to the STAs may originate from outside the BSS, mayarrive through the AP, and/or may be delivered to the STAs. The trafficoriginating from the STAs directed to destinations outside the BSS maybe sent to the AP to be delivered to the respective destinations.Traffic between STAs within the BSS may be sent through the AP. A sourceSTA may send traffic to the AP. The AP may deliver the traffic to adestination STA. The traffic between STAs within a BSS may bepeer-to-peer traffic. Such peer-to-peer traffic may be sent between thesource and destination STAs, e.g., with a direct link setup (DLS) usingan IEEE 802.11e DLS, an IEEE 802.11z tunneled DLS (TDLS), and/or thelike. A WLAN using an Independent BSS (IBSS) mode may have no APs, andthe STAs may communicate directly with each other. This mode ofcommunication may be referred to as an ad-hoc mode.

Using the IEEE 802.11 infrastructure mode of operation, the AP maytransmit a beacon on a fixed channel, e.g., the primary channel. Thischannel may be 20 MHz wide and may be the operating channel of the BSS.This channel may be used by the STAs to establish a connection with theAP. The channel access in an IEEE 802.11 system may be Carrier SenseMultiple Access with Collision Avoidance (CSMA/CA). In this mode ofoperation, the STAs, including the AP, may sense the primary channel. Ifthe channel is detected to be busy, the STA may back off. A single STAmay transmit at any given time in a given BSS.

In IEEE 802.11n, high throughput (HT) STAs may use a 40 MHz wide channelfor communication. This may be achieved by combining the primary 20 MHzchannel with an adjacent 20 MHz channel to form a 40 MHz wide contiguouschannel. IEEE 802.11n may operate on 2.4 GHz and/or 5 GHz industrial,scientific and medical (ISM) band.

In IEEE 802.11ac, very high throughput (VHT) STAs may support 20 MHz, 40MHz, 80 MHz, and/or 160 MHz wide channels. The 40 MHz and/or 80 MHzchannels may be formed, for example, by combining contiguous 20 MHzchannels. A 160 MHz channel may be formed, for example, by combiningeight contiguous 20 MHz channels, or by combining two non-contiguous 80MHz channels (e.g., which may be referred to as an 80+80 configuration).For the 80+80 configuration, the data (e.g., after channel encoding) maybe passed through a segment parser that may divide it into two streams.Inverse Fast Fourier Transform (IFFT) and/or time domain processing maybe performed on a stream (e.g., each stream), for example, separately.The streams may be mapped onto the two channels and the data may betransmitted. At the receiver this mechanism may be reversed, and thecombined data may be sent to the MAC. IEEE 802.11ac may operate on 5 GHzISM band.

IEEE 802.11af and IEEE 802.11ah may support sub 1 GHz modes ofoperation. The channel operating bandwidths may be reduced, for example,relative to those used in IEEE 802.11n and IEEE 802.11ac. IEEE 802.11afmay support 5 MHz, 10 MHz, and/or 20 MHz bandwidths in the TV WhiteSpace (TVWS) spectrum. IEEE 802.11ah may support 1 MHz, 2 MHz, 4 MHz, 8MHz, and/or 16 MHz bandwidths, for example, using non-TVWS spectrum.IEEE 802.11ah may support Meter Type Control (MTC) devices in a macrocoverage area. MTC devices may have capabilities including, for example,support for limited bandwidths and/or very long battery life.

In IEEE 802.11ad, very high throughput may use the 60 GHz band. A widebandwidth spectrum at 60 GHz may be available, which may enable veryhigh throughput operation. IEEE 802.11ad may support, for example, up to2 GHz operating bandwidths. The data rate for IEEE 802.11ad may reach upto 6 Gbps. The propagation loss at 60 GHz may be more significant thanat the 2.4 GHz and/or 5 GHz bands. Beamforming may be adopted in IEEE802.11ad, for example, to extend the coverage range. To support thereceiver requirements for this band, the IEEE 802.11ad MAC layer may bemodified, for example, to allow channel estimation training. This mayinclude omni (e.g., quasi-omni) modes of operation and/or beamformedmodes of operation.

WLAN systems may support multiple channels and channel widths, forexample, according to IEEE 802.11n. IEEE 802.11ac, IEEE 802.11af, IEEE802.11ah, and/or the like. WLAN systems may include a channel that maybe designated as the primary channel. The primary channel may have abandwidth that may be equal to the largest common operating bandwidthsupported by the STAs in the BSS. The bandwidth of the primary channelmay be limited by a STA that supports the smallest bandwidth operatingmode. In the example of 802.11ah, the primary channel may be 1 MHz wideif there are STAs (e.g., MTC type devices) that are limited tosupporting a 1 MHz mode, for example, even if the AP and/or other STAsin the BSS may support a 2 MHz, 4 MHz, 8 MHz, 16 MHz, or other channelbandwidth operating mode. The carrier sensing and/or Network AllocationVector (NAV) settings may depend on the status of the primary channel.If the primary channel is busy, for example, due to a STA supporting a 1MHz operating mode transmitting to the AP, the available frequency bandsmay be considered busy even though a majority of the bands may stay idleand available.

In the United States, for example, the available frequency bands thatmay be used by IEEE 802.11ah may range from 902 MHz to 928 MHz. InKorea, for example, the available frequency bands may range from 917.5MHz to 923.5 MHz. In Japan, for example, the available frequency bandsmay range from 916.5 MHz to 927.5 MHz. The total bandwidth available forIEEE 802.11ah may range from 6 MHz to 26 MHz, for example, and maydepend on the country code.

In multi-band operation, a communication session may be transferred froma 60 GHz frequency band to a lower frequency band, such as a 5 GHzfrequency band, for example. A multi-band capable device may manageoperation over one or more frequency bands. The multi-band capabledevice may support operation on multiple frequency bands, for example,simultaneously. The multi-band capable device may support operation onone frequency band at a time and may transfer between frequency bands.

A multi-band capable device may support multiple MAC sublayers. Themulti-band capable device may be coordinated by a multiple MAC stationmanagement entity (MM-SME). A multi-band management entity may bedefined in the SME and may be responsible for the operations and/orfunctions of fast session transfer (FST). There may be two FST modesdefined in IEEE 802.11ad, e.g., transparent FST and/or non-transparentFST. With transparent FST, the multi-band capable device may use thesame media access control (MAC) address on multi-bands. For example, thesource and the destination MAC addresses (e.g., in both the old and thenew frequency bands) may be the same. With non-transparent FST, one ormore bands in the device may utilize one or more MAC addresses.

A multi-band procedure may include one or more of the followingoperations between two or more (e.g., a pair) of multi-band capabledevices: setup, configuration, tear down, and/or transfer of FSTsessions from one frequency band to another. The on-channel tunneling(OCT) operation may allow a STA of a multi-band capable device totransmit a MAC management protocol data unit (MMPDU) that may beconstructed by a different STA of the same device. By using OCT, amulti-band capable device may encapsulate a packet and transmit it onanother frequency band. This may enable the SMEs of a pair of multi-bandcapable devices to provide a seamless FST.

FIG. 1 is a diagram of an example of a channel coordination mechanism. Acommon channel may be defined and the STAs and/or APs may operate on thecommon channel. For example, a device (e.g., STA A) may initiate atransmission by sending a request to switch (RTX) on a common channel toanother device (e.g., STA B). The RTX may carry the information aboutthe destination channel in which the transmission may take place. TheSTA B may reply with a clear to switch (CTX) on the common channel toaccept or reject the transmission request. The CTX may include theinformation about the destination channel. If STA A and STA B agree tothe transmission, the STAs may switch to the destination channel (e.g.,Channel m) within a pre-defined time period and perform transmission.After the transmission over the destination channel ends, the STA A andSTA B may switch back to the common channel.

In IEEE 802.11ai, the STAs may connect to a specific radio band. If theBSS load on the current band (e.g., 2.4 GHz) is not enough toaccommodate additional STAs, the AP may redirect the STAs to the AP onother band (e.g., 5 GHz), for example, by including the neighbor APinformation in the probe response and/or beacon so that the STAs mayscan and/or associate with the neighbor AP. The neighbor AP informationmay include one or more of the following: band ID, operation class,channel list, target beacon transmission time (TBTT) of the APs,interworking information element (IE) of the AP, and/or the like.

IEEE 802.11aj may provide enhancements for very high throughput tosupport, for example, one or more 40-50 GHz and/or 59-64 GHz frequencybands (e.g., Chinese frequency bands). Beamforming training for amultiband capable millimeter wave device, which may usually be performedfor 45 GHz and/or 60 GHz transmission, may be completed with the help ofa 2.4 GHz/5 GHz band. For example, the beamforming training feedbackframes may be transmitted via a 2.4 GHz/5 GHz band.

Devices may support operation on different frequency channels withdifferent channel bandwidths and/or may provide different transmissiondata rates, for example, in IEEE 802.11. For example, IEEE 802.11ad maysupport very high data rates (e.g., up to 6 Gbps) and/or may operate inthe 60 GHz frequency band. Due to the nature of the propagation loss inthe 60 GHz frequency band, the typical coverage range may be short(e.g., 10 meters). IEEE 802.11n/ac may operate in the 2.4 GHz/5 GHzfrequency band, which may support high data rates with better coveragethan that of IEEE 802.11ad. Sub-1 GHz transmissions (e.g., IEEE802.11ah, IEEE 802.11af, and/or the like) may provide good coveragerange, while the data rate may be limited. IEEE 802.11aj may providevery high throughput to support bands, for example, 40-50 GHz and/or59-64 GHz frequency bands (e.g., Chinese frequency bands).

The coverage range of beamformed transmission and/or omni transmissionwithin the same frequency band may be different. Beamforming may extendthe coverage range in one or more directions. Omni transmissions (e.g.,quasi-omni transmissions) may provide uniform coverage in one or more ofthe directions (e.g., all/each of the directions). A quasi-omnitransmission may refer to an omni-transmission where uniform coverage isprovided in substantially all of the directions. FIG. 2 is a diagram ofan example of omni range transmission. A Request to Send (RTS) and/orClear to Send (CTS) may be transmitted via an omni antenna pattern. Theomni antenna may not provide full protection for beamformedtransmissions. For example, diagram 200 may illustrate an example of therange of an omni transmission 201 and an example of the range of abeamformed transmission 202. The coverage range of the beamformedtransmission 202 may be larger than the coverage range of the omnitransmission 201. As such, one or more users 203 who may be out of thecoverage range of a RTS and/or CTS (e.g., which may be sent via an omnitransmission pattern) may face interference from beamformedtransmissions 202.

Beamforming training (e.g., beam-switch based beamforming training) mayintroduce extra interference to neighboring co-channel transmissions.For example, with IEEE 802.11ad, the beamforming training may beperformed by sweeping one or more beam sectors. The coverage range ofthe beamforming training may cover one or more directions (e.g., each ofthe directions) and/or may be larger than the omni transmission. Thebeamforming training may not be protected by WLAN protection mechanisms,for example, such as omni RTS and/or CTS transmitted on the samefrequency band. The beamforming training may create extra interferenceto other devices operating in the same frequency band and/or may bevulnerable to transmissions from other devices.

An AP may announce its presence and/or its BSS's operating parameters,for example, by transmitting beacon frames. An AP may transmit beaconframes using a sectorized antenna beam pattern, for example, in order toextend coverage. Due to the limited beamwidth of the sectorized antennabeam patterns, a complete sweep of the coverage area of an AP may, forexample, take several beacon intervals, which may lead to delays in theAP discovery process.

A device that is capable of transmitting and/or receiving on multiplefrequency bands may choose to operate on the multiple bands in parallel.The operations on multiple-bands may be independent. For example, a dualband WiFi AP may operate on a 2.4 GHz band and a 5 GHz band, which maybe equivalent to having two co-located APs, one operating on a 2.4 GHzband and another operating on a 5 GHz band, for example, with or withoutcooperation between the two APs.

Multiple bands may be allowed to cooperate such that the transmissionson the one or more bands may be more efficient. Multiband operation(e.g., cooperative multiband operation) may consider the characteristicsof one or more bands (e.g., each band). For example, a band with longercoverage range but limited bandwidth may be utilized to carry controland/or management information. A band with shorter coverage range andlarge bandwidth may be utilized to carry data traffic. A band with lessinterference may be used for control information. A band with moreinterference may be used for data transmission.

FIG. 3 is a diagram of an example reference model for transparentmultiband operation. The architecture, for example, may be associatedwith an IEEE 802.11ad reference model for transparent multibandoperation. The multiband management sublayer may be located in the upperMAC. The upper MAC may be in charge of the coordination of one or moreMAC sublayers. Reference models similar to the example reference modelillustrated in FIG. 3 may be used.

Directional transmission may be adopted as a mode for transmission(e.g., an optional or mandatory mode for transmission). Directionaltransmission may depend on the characteristics of the frequency band.For example, with IEEE 802.11ad, directional transmissions on a 60 GHzfrequency band may be mandatory and training procedures for suchdirectional/beamforming transmission may be mandatory. Directionaltransmission and/or training for directional transmission may introduceextra interference in the system. For example, a STA may transmit atraining frame multiple times using the lowest modulation and codingscheme (MCS) level and/or maximum power. A STA may sweep multipletransmit antenna sectors. This may create interference in the directionsthe transmit antenna sectors may point in. The transmission may not beprotected (e.g., entirely protected) using the omni RTS/CTS signals onthe same band, for example, because the coverage range of omnitransmission may be less than that of sectorized and/or directionaltransmission (e.g., as described with reference to FIG. 2).

The propagation loss of radio signals in different frequency bands mayvary. FIG. 4 is a diagram of an example path loss models that may beused in one or more WiFi channels. For example, the path loss model 400of FIG. 4 may be used in WiFi channels on 60 GHz, 5 GHz and/or 900 MHzfrequency bands. As illustrated by example in FIG. 4, the coverage rangeof the 60 GHz bands 401, 402 may be less than that of the 5 GHz band 403and/or the 900 MHz bands 404, 405, 406. With the beamforming gain, thecoverage range of the 60 GHz band transmissions may be less than the 5GHz band transmissions. As such, the power controlled and/or MCScontrolled omni transmissions (e.g., RTS, CTS, and/or the like) on the 5GHz band and/or a 900 MHz band may be used to protect the directionaltransmission on the 60 GHz band.

FIG. 5 is a diagram of an example MCS controlled and/or power controlledRTS/CTS transmission on a 5 GHz band to protect the beamforming and/orbeamforming training transmissions on a 60 GHz band. In order to protectthe beamforming and/or beamforming training transmission on the 60 GHzband, RTS and/or CTS protection (e.g., which may be RTS/CTS-likeprotection) may be provided on a different frequency band, for example,a 5 GHz band. For example, the diagram 500 illustrates an examplecoverage area of omni transmission via a 60 GHz band 501, an example ofthe range of beamforming transmission via the 60 GHz band 502, and thecoverage area of omni transmission via a 5 GHz band 503. A user 504(e.g., a WTRU) outside the coverage area of omni transmission on the 60GHz band 501, but within the range of a beamforming transmission on the60 GHz band 502, may be protected via RTS and/or CTS protection via omnitransmission on the 5 GHz band 503. As such, RTS and/or CTS protectionmay provide one or more users 504 within the coverage range of abeamformer and/or a beamformed to set their NAV accordingly. RTS and/orCTS protection may provide protection on directional training and/ortransmission. The RTS and/or CTS protection may be MCS controlled and/orpower controlled, for example, such that the maximum coverage range ofthe protection frames may be equal to the maximum coverage range of thedirectional transmission protected. Although described with reference toa 5 GHz band and a 60 GHz band, the example of FIG. 5 may be applicableto omni transmission via a first band and directional transmission via asecond band, where for example, the first band may be of a lowerfrequency than the second band.

Multiband RTS (MRTS) and/or multiband CTS (MCTS) may be used fordirectional transmission protection using multiband operation. FIG. 6 isa diagram of an example MRTS and/or MCTS protected directional trainingand/or transmission. In the example diagram 600 of FIG. 6, a stationSTA1 601 and a station STA2 602 may intend to perform beamformingtraining, for example, on a 60 GHz band. The stations STA1 601 and STA2602 may use MRTS and/or MCTS transmitted on a 5 GHz band to scheduleand/or protect the 60 GHz band transmission, for example, to protect oneor more unintended STAs 603 from interference caused by directionaltraining and/or other transmissions on the 60 GHz band. One or more ofthe following may apply.

The STA1 601 may transmit a request on the 5 GHz band to the STA2 602.The request may be associated with a different frequency band from whichit is sent. For example, the request may be sent via a first frequencyband (e.g., the 5 GHz band) and may be associated with a secondfrequency band (e.g., the 60 GHz band). The request may include a MRTStransmission, for example, MRTS frame 604. The MRTS frame 604 may besent via the 5 GHz band but may be associated with the 60 GHz band. Forexample, the request (e.g., the MRTS frame 604) may be associated with abeamforming transmission (e.g., beamforming transmission 609 and/orbeamforming transmission 610) that may be scheduled to be sent via the60 GHz band. A beamforming transmission may include one or morebeamforming training signals, beamforming transmission signals, and/orthe like. For example, a beamforming signal 613 may be an example of abeamforming training signal or a beamforming transmission signal ofbeamforming transmission 609. The STA1 601 may send the MRTS frame 604on the 5 GHz band and the MRTS frame 604 may be associated with atransmission (e.g., a beamforming training signal) on the 60 GHz band.The STA1 601 may schedule the transmission (e.g., a beamformingtransmission, such as a transmission of one or more beamforming trainingsignals) on the 60 GHz band by indicating an allocation start timeand/or duration of the transmission (e.g., the beamforming transmission)via the MRTS frame 604.

The request may be for a transmit opportunity (TxOP) reservation. TheTxOP reservation may be a reservation for a transmission on a frequencyband that may different from the frequency band of the request. Forexample, the request may be sent via the 5 GHz band and the request maybe for a TxOP reservation for the 60 GHz band. For example, STA1 601 maysend a request on a first frequency band (e.g., the 5 GHz band) for aTxOP reservation for a second frequency band (e.g., the 60 GHz band).The TxOP reservation may be a reservation to perform beamformingtraining and/or beamforming transmissions (e.g., send and/or receive oneor more beamforming transmissions) on the second frequency band.

The STA2 602 may receive the request transmitted via the 5 GHz band. Forexample, the STA2 602 may receive the MRTS frame 604 transmitted via the5 GHz band. The STA2 602 may determine that the received MRTS frame 604may be a packet for itself, for example, by checking the MAC header ofthe MRTS frame 604. The STA2 602 may accept or reject the request (e.g.,the TxOP reservation, the scheduling of the beamforming schedule on the60 GHz band, etc.), for example, according to one or more of thefollowing. The STA2 602 may transmit a MCTS frame 605 to the STA1 601,for example, via the 5 GHz frequency band, which when received, mayindicate that the STA2 602 accepts the request. The STA2 602 maytransmit the MCTS frame 605 one short inter-frame space (SIFS) after theMRTS frame 604. The MCTS frame 605 may include a field that indicateswhether STA2 602 accepts or rejects the schedule. The STA2 602 maytransmit the MCTS frame 605 back to the STA1 601, for example, when STA2602 accepts the schedule (e.g., only when the STA2 602 accepts theschedule). The STA1 601 may determine that STA2 602 rejects theschedule, for example, if the STA1 601 does not receive the MCTS frame605 within an MCTS timeout period.

The one or more unintended STAs 603 may receive the request (e.g., theMRTS frame 604) from the STA1 601 sent via the 5 GHz band. The one ormore unintended STAs 603 may be within the range of a 5 GHz omni (e.g.,quasi-omni) transmission, but may not be within the range of a 60 GHzomni transmission. The unintended STAs 603 may determine that therequest (e.g., the MRTS frame 604) is not intended for them, forexample, by checking the MAC header of the MRTS frame 604. Theunintended STAs 603 may set their NAV 606 on the 5 GHz band to avoidinterfering with the MCTS frame 605 sent by the STA2 602 to the STA1 601in response to the request (e.g., the MRTS frame 604).

If STA1 601 and STA2 602 agree with the transmission on the 60 GHz band(e.g., the TxOP), then STA1 601 and STA2 602 may begin the transmission(e.g., the beamforming transmission), for example, over the scheduledperiod 607. The transmission on the 60 GHz band may not follow (e.g.,immediately follow) the transmission of the MRTS frame 604 and/or theMCTS 605 frame. The one or more unintended STAs 603, which may bemultiband capable, may set their NAVs 608 on the 60 GHz band over theschedule period 607, for example, to avoid interfering with thescheduled transmission and/or to avoid receiving interference from theschedule transmission between STA1 601 and STA2 602. Further, theunintended STAs 603 may set their NAV on the 60 GHz band, for example,according to the allocation start time and/or duration of the allocationidentified in MRTS 604 and/or MCTS 605 transmissions. As such, the STA1601 and STA2 602 may perform the scheduled transmission (e.g.,beamformed transmission) on the 60 GHz band without causing interferenceto and/or receiving interference from the one or more unintended STAs603.

The STA1 601 may send the transmission in accordance with the request(e.g., the MRTS frame 604), for example, via the 60 GHz band. Thetransmission may be a beamforming transmission, which may include one ormore beamforming signals (e.g., a sequence of beamforming trainingsignals, a sequence of beamforming transmission signals, and/or thelike). The transmission may be transmitted to a region associated withthe STA2 602. For example, the STA1 601 may send the beamformingtransmission 609 (e.g., which may include one or more frames, forexample, beamforming training signal 613) on the 60 GHz band. The STA2602 may receive the beamforming transmission 609. The STA2 602 may senda beamforming transmission 610 (e.g., which may include one or moreframes) on the 60 GHz band, for example, one SIFS after the completionof the beamforming transmission 609. The STA1 601 may receive thebeamforming transmission 610. The STA1 601 may reply with an ACK frame611, for example, if it successfully receives the transmission 610. TheSTA2 602 may reply with an ACK frame 612, for example, if itsuccessfully receives the transmission 609.

The example of MRTS/MCTS protected directional training and/ortransmission described herein may be applied to devices transmitting onmultiple frequency bands, for example, where one band may be associatedwith (e.g., may use) a quasi-omni transmission and another band may beassociated with (e.g., may use) a directional transmission. Therefore,although 5 GHz and 60 GHz bands are used as an example in reference toFIG. 6, other frequency bands may be used.

The STA1 601 may receive a beamforming schedule, for example, via an AP.A beamforming schedule may refer to a beamforming training scheduleand/or a beamforming transmission schedule. The beamforming trainingschedule and/or the beamforming transmission schedule may include astart time, a duration, a frequency band, and/or the like of abeamforming transmission (e.g., the beamforming transmission 609 and/orthe beamforming transmission 610). The STA1 601 may receive thebeamforming training schedule and/or the beamforming transmissionschedule before transmitting a request (e.g., the MRTS frame 604) to theSTA2 602 over the 5 GHz band, for example, if STA1 601 is a non-AP STA.

A STA may be an AP or a non-AP. For example, if a STA (e.g., STA1 601)is a non-AP STA, then it may receive a beamforming training scheduleand/or a beamforming transmission schedule from an AP. If a STA (e.g.,STA1 601) is an AP, then it may begin transmitting a request (e.g., aMRTS) without receiving a beamforming training schedule and/or abeamforming transmission schedule from an AP.

One or more MRTS and/or MCTS frame formats may be disclosed. MRTS and/orMCTS frames may be used, for example, to reserve a time slot fortransmission on another frequency band. The scheduling informationand/or frequency band information may be included in the body of theMRTS and/or MCTS frame. The MRTS and/or MCTS frames may include, forexample, the schedule element field and/or multiband element field. Theschedule element field may include one or more of an allocation start,an allocation block duration, a number of blocks, an allocation blockperiod, and/or the like.

The multiband element field may be used to carry the information of theband used for beamforming training and/or transmission. The multibandelement may include one or more of a multiband control field, a band IDfield, a channel ID field, a BSSID field, a STA MAC address, and/or thelike. The multiband control field may include one or more of thefollowing. The multiband control field may include a STA role field. TheSTA role field may specify the role the transmitting STA may play on thetarget channel, for example, whether the STA may be an AP, a personalbasic service set coordination point (PCP) or a non AP/PCP STA, and/orthe like. The multiband control filed may include a STA MAC addresspresent field. The multiband control field may include a pairwise ciphersuit present field.

The band ID field may indicate the frequency band in which thebeamforming training and/or transmission may take place. For example,the band ID field may be used to indicate that the 60 GHz frequency bandmay be the band for beamforming training and/or transmission. Thechannel ID field may indicate the frequency channel(s) in the frequencyband indicated by the band ID that may be utilized for beamformingtraining and/or transmission. The BSSID field may specify the BSSID ofthe BSS operating on the channel and/or frequency band indicated by theband ID and/or the channel ID. The STA MAC address may indicate the MACaddress of the STA in the band specified in the element. The STA MACaddress may be the same as the MAC address of the operating band.

As such, the MRTS frame and/or the MCTS frame may include one or more ofthe following: a schedule element field, a multiband control field, aband identification (ID) field, a channel ID field, a band service setidentification (BSSID) field, a station (STA) media access control (MAC)address field, and/or the like.

Extended multi-user MRTS/MCTS may be provided. A transmission sent via afirst band (e.g., a MRTS frame and/or a MCTS frame on a 5 GHz band) mayschedule a transmission on a second band (e.g., a beamformingtransmission on a 60 GHz band), for example, for multiple users. FIG. 7is a diagram 700 of an example use of MRTS/MCTS frames on a 5 GHz bandto schedule transmissions on a 60 GHz band. The diagram 700 may besimilar to the diagram 600, except the diagram 700 may illustrate anexample of a multi-user (e.g., AP, 701 scheduling with STA1 702 and STA2703) embodiment. The transmission on the 5 GHz band may follow theCSMA/CA protocol, while the transmission on the 60 GHz band may becontention free based. One or more of the following may be provided.

An AP 701 may transmit a request on a 5 GHz band to schedule amulti-user transmission on a 60 GHz band. The request may include a MRTSframe 704. The request (e.g., the MRTS frame 704) may include theschedule elements for STA1 702 and STA2 703 on the 60 GHz band. STA1 702may receive the request (e.g., the MRTS frame 704) on the 5 GHz band.The STA1 702 may determine (e.g., according to the MRTS frame 704) thatthe AP 701 intends to transmit a 60 GHz frame 707 to STA1 702 on the 60GHz band at a determined time, for example, at time slot x1. STA1 702may accept or reject this schedule, for example, as described herein.For example, STA1 702 may accept the schedule by transmitting MCTS frame705 to the AP 701, for example, one SIFS after the MRTS frame 704.

The STA2 703 may receive the MRTS frame 704 on the 5 GHz band. The STA2703 may determine (e.g., according to the MRTS frame 704) that the AP701 intends to transmit a 60 GHz frame 708 to STA2 703 on the 60 GHzband at a determined time, for example, at time slot x2. The STA2 703may determine that it may be the second user in the multi-userscheduling. The STA2 703 may wait for the STA1 702 to send a MCTS frame705. For example, the STA2 703 may send its own MCTS frame 706 one SIFSafter the completion of the MCTS frame 705 from STA1 702. For example,the STA2 703 may wait for the AP 701 to send a poll frame and the STA 2703 may reply by transmitting the MCTS frame 706.

The AP 701 may transmit a frame 707 on the 60 GHz band at time slot x1.The STA 702 may reply with an ACK frame 709, for example, if itsuccessfully detected the frame. The AP 701 may transmit a frame 708 onthe 60 GHz band at time slot x2. The STA2 703 may reply with an ACKframe 710, for example, if it successfully detected the frame. The frame707 and/or the frame 708 may include one or more frames, for example,the frame 707 and/or the frame 708 may be a beamforming transmissionthat includes one or more beamforming training signals (e.g., asdescribed with reference to FIG. 6).

The AP 701 may arrange multi-user transmissions on the 60 GHz bandsequentially in this example. For example, the transmissions to the STAs702, 703 may be separable in the time domain in FIG. 7. In one or moreembodiments, the transmissions to the STAs 702, 703 may be separable inthe frequency domain, the spatial domain, the code domain, and/or thetime domain.

The AP 701 may use a group ID to signal a group of users (e.g., STAs)within a scheduling group. The group ID may be defined and maintained bythe AP 701. The group ID may be included in the SIG field of thephysical layer convergence protocol (PLCP) header.

Dedicated MRTS/MCTS for 60 GHz band beamforming training may beprovided. With IEEE 802.11ad, directional/beamforming transmission maybe used. To support directional/beamforming transmission, beamformingtraining implementations may be used, which for example, may introduceoverhead and/or may cause interference for the co-channel STAs. A sectorlevel sweep (SLS) may be utilized for coarse beamforming training. In aSLS, sector sweep (SSW) frames may be utilized for transmit beamformingtraining and/or receive beamforming training. For transmit beamformingtraining, SSW frames may be transmitted and/or multiple antenna sectors(e.g., beams) may be swept. The receiver may select the best antennasectors according to received signal strength and/or may send thisinformation to the transmitter, for example, as feedback. For receivebeamforming training, the SSW frames may be repeated N times using thebest transmit antenna sector, the receiver may sweep the receive antennasectors, and/or the receiver may select the best antenna sector (e.g.,according to received signal strength). To protect the co-channel STAsfrom interference introduced by beamforming training, MRTS/MCTSprotected directional training (e.g., as illustrated in FIG. 6) may beused. The MRTS/MCTS protected directional training may be extendedfurther, which may allow additional overhead saving for BF training.

FIG. 8 is a diagram of an example dedicated MTRS/MCTS for a 60 GHzsector level sweep training. The MRTS/MCTS frames and/or the SSW framesmay be modified. The modified SSW frame may be referred to as a null SSWframe. The dedicated MRTS and/or MCTS frames defined for SLS trainingmay include an SSW field and/or an SSW feedback field. The SSW field maybe transmitted in the SSW frame and may indicate the directionalmultigigabit (DMG) antenna IDs and/or sector IDs that may be utilizedfor the SSW frame transmission. The SSW feedback field may includeinformation that may be used for SSW feedback frames.

In IEEE 802.11ad, the SSW field and/or SSW feedback field may be carriedby one or more SSW frames. The MRTS/MCTS frames may be transmitted on adifferent frequency band of the same or different WLAN specification.The null SSW frames may be SSW frames with the MAC body removed. Thenull SSW frames may be SSW frames with the short training field (STF),channel estimation (CE) field, and/or header field kept the same as theSSW frames.

In the example diagram 800 of FIG. 8, a station STA1 801 and a stationSTA2 802 may perform beamforming training using the SLS scheme on a 60GHz band. The stations STA1 801 and STA2 802 may use MRTS and/or MCTStransmitted on a 5 GHz band to schedule and/or protect the 60 GHz bandtransmission, for example, to protect one or more unintended STAs 803from interference caused by directional training and/or transmission onthe 60 GHz band. One or more of the following may apply.

The STA1 801 may transmit a request on the 5 GHz band to STA2 802, whichfor example, may schedule a transmission (e.g., a beamformingtransmission) on the 60 GHz band. The request may include a MRTS frame804. For example, the STA1 801 may schedule a beamforming transmissionon the 60 GHz band by indicating an allocation start time and/orduration of the beamforming transmission via the MRTS frame 804. TheSTA2 802 may receive the MRTS frame 804. The STA2 802 may determine thatthe received MRTS frame 804 may be a packet for itself, for example, bychecking the MAC header of the MRTS frame 804.

The STA2 802 may accept or reject the scheduling on the 60 GHz bandtransmission, for example, according to one or more of the following.The STA2 802 may transmit a MCTS frame 805 to the STA1 801, for example,one SIFS after the MRTS frame 804. The MCTS frame 805 may include afield that indicates whether STA2 802 accepts or rejects the schedule.The STA2 802 may transmit the MCTS frame 805 back to the STA1 801, forexample, when STA2 802 accepts the schedule. The STA1 801 may determinethat STA2 802 rejects the schedule, for example, if STA1 801 does notreceive the MCTS frame 805 within the MCTS timeout period. The MRTS 804and/or MCTS 805 may be a modified MRTS and/or MCTS, for example,modified to include a SSW field and/or a SSW feedback field.

The one or more unintended STAs 803 may receive the MRTS frame 804 fromthe STA1 801. The one or more unintended STAs 803 may be within therange of a 5 GHz omni transmission, but not within the range of a 60 GHzomni transmission. The unintended STAs 803 may determine that the MRTSframe 804 is not intended for them, for example, by checking the MACheader of the MRTS frame 804. The unintended STAs 803 may set their NAV806 on the 5 GHz band to avoid interfering with the MCTS frame 805 sentby the STA2 802 to the STA1 801 in response to the MRTS frame 804.

If STA1 801 and STA2 802 agree with the scheduled transmission on the 60GHz band, then STA1 801 and STA2 802 may begin transmission (e.g.,beamforming transmission) over the scheduled period 812. The scheduledtransmission on the 60 GHz band may not follow (e.g., immediatelyfollow) the transmission of the MRTS frame 804 and/or the MCTS 805frame. The one or more unintended STAs 803, which may be multibandcapable, may set their NAVs 808 on the 60 GHz band over the scheduleperiod 812, for example, to avoid interfering with the scheduledtransmission and/or to avoid receiving interference from the scheduletransmission between STA1 801 and STA2 802.

The STA1 801 may transmit the one or more SSW frames 807 (e.g., thebeamformed transmission) on the 60 GHz band. The STA2 802 may transmitthe one or more SSW frames 808 (e.g., the beamformed transmission) onthe 60 GHz band, for example, one SIFS after the completion of the SSWtransmission 807 by STA1 801. The SSW frames 808 may include informationrelating to an antenna sector (e.g., the best antenna sector) for abeamforming training schedule. The SSW frames 807, 808 may be modified,for example, the SSW frames 807, 808 may include one or more Null SSWframes. The STA1 801 may reply with an ACK frame 810, for example, if itsuccessfully receives the SSW transmission 808. The STA2 802 may replywith an ACK frame 811, for example, if it successfully receives the SSWtransmission 807. As such, the STA1 801 and STA2 802 may perform thescheduled transmission (e.g., a beamformed transmission including theSSW frames) on the 60 GHz band without causing interference to and/orreceiving interference from the one or more unintended STAs 803.

A beamforming transmission (e.g., as described with reference to FIG. 6)may include one or more SSW frames, for example, as described inreference to FIG. 8. For example, the beamforming signal (e.g.,beamforming training signal) 613 may include a SSW frame.

The example of MRTS/MCTS protected directional training and/ortransmission described herein may be applied to devices transmitting onmultiple frequency bands, for example, where one band may use omnitransmission and another band may use directional transmission.Therefore, although 5 GHz and 60 GHz bands are used as an example, otherfrequency bands may be used.

Multiband aided AP/STA discovery may be provided. When a device isequipped with multiple WiFi interfaces, for example, including differentSTAs that may adhere to different WLAN standards, the STAs within thecoverage range of the multi-band device (MBD) may have differentcharacteristics, for example, such as coverage area, omni-directional ordirectional beamwidth capabilities, data rates, etc. The differentcharacteristics may be leveraged to aid and/or to speed up the APdiscovery for a STA within multi-band devices.

For example, a multi-band device (e.g., MBD1) may include a STA (e.g.,STA1-B1, operating on frequency band 1 (B1)), and another STA (e.g.,STA1-B2, operating on frequency band 2 (B2)). The STA1-B1 may utilize onchannel tunneling (OCT) to instruct the STA1-B2 to conduct scanning forother multi-band devices (e.g., MBD2) that may have STAs on the B1 andB2 bands. The MBD2 may have, for example, STA2-B1 operating on B1 andSTA2-B2 operating on B2. The OCT scanning may establish links and/orassociations, e.g., between STA1-B1 and STA2-B1 that may not beassociated (e.g., currently associated).

In order to speed up the OCT AP discovery process, a scanning MBD (e.g.,MBD1) may include a parameter, for example, a RESTRICTIONS in the OCTMLME-SCAN.request in the form of, for example, a parameter (e.g., eachparameter) specified for MLME-SCAN.request (e.g., as per 802.11ad), apeer multi-band element (e.g., as per 802.11ad), a local multi-bandelement (e.g., as per 802.11ad), a channel specific multi-band element(e.g., as per 802.11ac), a RESTRICTIONS, and/or the like.

The RESTRICTIONS may include one or more (e.g., a set) of parametersrestricting the scanning process. The RESTRICTIONS may be implemented indifferent ways, for example, depending on characteristics of the STAsand/or the WLAN specification with which the STAs may be attempting toestablish a link/association. For example, if IEEE 802.1 ad STAs,STA1-B1 and STA2-B1 may be operating on 60 GHz band and the RESTRICTIONSmay include one or more of the distance between STA1-B1 and STA2-B1, anangle of arrival, a sector ID, and/or the like. The distance betweenSTA1-B1 and STA2-B1 may be included in MBD1 and MBD2 (e.g.,respectively). The distance between MBD1 and MBD2 may be derived from aninterpretation of receive power parameters, for example, such as RSSI,RCPI, RPI, etc. For angle of arrival, scanning may be limited toscanning for MBDs within certain angles of arrival. For Sector ID,scanning may be limited to scanning for MBDs/STAs within a certainsector(s), for example, which may be identified by Sector ID(s). Similarrestrictions may be used for IEEE 802.11aj STAs operating on anotherfrequency band, for example, a 45 GHz band. Channel specific bandrestrictions may be used. For example, multi-band associations may berestricted to use by the primary channel in a VHT type device, forexample, such as a STA that may support multi-band operation using avariation of the IEEE 802.11ac and/or IEEE 802.11ad specifications.

The BSSDescriptions in the OCT MLME-SCAN.confirm may be expanded withparameters, such as Discovery Information. The Discover Information mayinclude one or more of the distance between STAs (e.g., STA1-B1 andSTA2-B1), the angle of arrival, the sector ID(s), and/or the like. Thedistance between STAs (e.g., STA1-B1 and STA2-B1) may be included inMBD1 and MBD2, e.g., respectively. The distance between MBD1 and MBD2may be derived from an interpretation of the receive power parameters,for example, such as the received signal strength indicator (RSSI), thereceived channel power indicator (RCPI), the received power indicator(RPI), etc. The angle of arrival of STA2-B2's transmission when receivedat STA1-B2 may indicate the relative position of MBD1 and MBD2. TheSector ID may include, for example, the transmitting sector ID of theSTA2-B2's transmission and/or a receiving Sector ID(s) when received atSTA1-B2.

The discovery may be limited to discovery between category, types,and/or classes of STAs. For example, a STA may be categorized as one ormore of a meter type, a backhaul type, an offload type, a highthroughput type device, a relay, and/or the like. Discovery may includeadditional restrictions using this information. A multi-band APdiscovery (e.g., an expedited multi-band AP discovery) may include oneor more of the following.

An MBD (e.g., MBD1) may want to establish link/association for one ormore of its STAs (e.g., STA1-B1) operating on B1 band with another MBDoperating on B1 and B2 bands. A MBD's SME (e.g., MBD1's SME) may send aMLME-SCAN.request to NT-MLME with parameters suitable for STA1-B1. TheMLME-SCAN.request may include the parameter RESTRICTIONS. The NT-MLME(non-transmitting MLME) may send an OCT MLME-SCAN.request including theparameter RESTRICTIONS to the TR-MLME (Transmitting MLME). For example,the MBD1 may include a STA1-B2, which may be an IEEE 802.11ad STAoperating on a 60 GHz band, and a STA1-B1, which may be an IEEE 802.11acSTA operating on a 5 GHz band. In this case, the NT-MLME may be an IEEE802.11ad MLME and the TR-MLME may be an IEEE 802.11ac MLME. SinceSTA1-B1 may have a coverage range of approximately 10 m, the parameterRESTRICTIONS may be a distance of approximately 10 m, or a RSSI, a RCPI,and/or a RPI associated with a propagation distance that may be equal toor shorter than approximately 10 m. The STA(s) may restrict theiroperation to one or more channels, for example, as indicated in theparameters for RESTRICTIONS. A STA may recommend to the AP a specificchannel for the discovery that may be determined by the STA as havingsuitable characteristics for the discovery procedure. For example, anarrow band channel may support a longer range than other availablechannels.

The TR-MLME may conduct active and/or passive scanning according to thescanning mode specified. One or more of the following may apply. TheTR-MLME may use a specific scanning based on the parameter RESTRICTIONSin the OCT MLME-SCAN.request, for example. If the parameter RESTRICTIONSis RSSI, RCPI, and/or RPI based, the TR-MLME may record APs of which thepackets, beacons, etc., satisfy the RSSI, RCPI, and/or RPI requirementsin passive scanning. In active scanning, the TR-MLME may include aRESTRICTIONS element in its probe request frames, which may solicitprobe responses from STAs, APs, and/or PCPs that have received the proberequest frames beyond a RSSI, RCPI, and/or RPI level. If the parameterRESTRICTIONS is angle of arrival and/or sector ID based, the TR-MLME mayuse beamformed transmissions of probe request to solicit responses fromSTAs, APs, and/or PCPs within a certain region of the coverage area. Ifthe parameter RESTRICTIONS is based of STA types, the TR-MLME mayinclude a RESTRICTIONS information element (IE) in its probe requestframe to solicit responses from certain types of STAs. When a STAreceives such a probe request frame with a RESTRICTIONS element, it mayrespond if it satisfies the RESTRICTIONS specified in the RESTRICTIONSelement.

For a BSS and/or STA, the TR-MLME may measure and/or record thefollowing discovery info, for example, based on the measurement atSTA1-B2, which for example may be an IEEE 802.11ac STA operating on the5 GHz band. One or more of the distance between stations, the angle ofarrival, the sector ID, the STA type, and/or the like may be included.The distance between STA1-B and STA2-B1 that may be included in MBD1 andMBD2, e.g., respectively. The distance between MBD1 and MBD2 may bederived from an interpretation of the receive power parameters, forexample, such as RSSI, RCPI, RPI, and/or the like. The angle of arrivalmay relate to the angle of arrival of STA2-B2's transmission whenreceived at STA1-B2, which may indicate the relative positions of MBD1and MBD2. The Sector ID may include, for example, the transmittingsector ID of the STA2-B2's transmission and/or a receiving Sector IDwhen received at STA1-B2. The STA type may report the type of the STAbeing reported.

The TR-MLME may provide Discovery Information for a (e.g., each)BSSDescription using the OCT MLME-SCAN.confirm primitive to the NT-MLMEand/or to the SME. This may be at the end of the scanning process and/orwhen an AP and/or BSS may be discovered. A STA (e.g., STA1-B1) may usethe Discovery Information to send out a probe request, a DMG beacon,and/or the like, to another STA (e.g., STA2-B1). The STA1-B1 may startfine beam training with STA2-B1 directly, for example, if sufficientinformation may have been obtained on the relative position of theSTA2-B1, which may be a part of MBD2. The STA1-B1 may conductassociation directly with STA2-B1, which may be a part of MBD2, forexample, if sufficient information is obtained from the discovery info.The STA1-B1 may conduct DLS/TDLS link establishment, relay negotiations,and/or establish robust security network association (RSNA) withSTA2-B1, which may be a part of MBD2, for example, if sufficientinformation is obtained from the Discovery Information.

Although the examples described with reference to FIGS. 6-8 may useSIFS, in one or more embodiments other IFSs may be used. For example,IFS of varying sizes may be used during MRTS and/or MCTS protecteddirectional training and/or transmission, for example, as described withreference to FIGS. 6-8.

FIG. 9A is a diagram of an example communications system 900 in whichone or more disclosed embodiments may be implemented. The communicationssystem 900 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 900 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems900 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 9A, the communications system 900 may include wirelesstransmit/receive units (WTRUs) 902 a, 902 b, 902 c, and/or 902 d (whichgenerally or collectively may be referred to as WTRU 902), a radioaccess network (RAN) 903/904/905, a core network 906/907/909, a publicswitched telephone network (PSTN) 908, the Internet 910, and othernetworks 912, though it will be appreciated that the disclosedembodiments contemplate any number of WTRUs, base stations, networks,and/or network elements. Each of the WTRUs 902 a, 902 b, 902 c, 902 dmay be any type of device configured to operate and/or communicate in awireless environment. By way of example, the WTRUs 902 a. 902 b, 902 c,902 d may be configured to transmit and/or receive wireless signals andmay include wireless transmit/receive unit (WTRU), a mobile station, afixed or mobile subscriber unit, a pager, a cellular telephone, apersonal digital assistant (PDA), a smartphone, a laptop, a netbook, apersonal computer, a wireless sensor, consumer electronics, and thelike.

The communications systems 900 may also include a base station 914 a anda base station 914 b. Each of the base stations 914 a, 914 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 902 a, 902 b, 902 c, 902 d to facilitate access to one or morecommunication networks, such as the core network 906/907/909, theInternet 910, and/or the networks 912. By way of example, the basestations 914 a, 914 b may be a base transceiver station (BTS), a Node-B,an eNode B, a Home Node B, a Home eNode B, a site controller, an accesspoint (AP), a wireless router, and the like. While the base stations 914a. 914 b are each depicted as a single element, it will be appreciatedthat the base stations 914 a, 914 b may include any number ofinterconnected base stations and/or network elements.

The base station 914 a may be part of the RAN 903/904/905, which mayalso include other base stations and/or network elements (not shown),such as a base station controller (BSC), a radio network controller(RNC), relay nodes, etc. The base station 914 a and/or the base station914 b may be configured to transmit and/or receive wireless signalswithin a particular geographic region, which may be referred to as acell (not shown). The cell may further be divided into cell sectors. Forexample, the cell associated with the base station 914 a may be dividedinto three sectors. Thus, in one embodiment, the base station 914 a mayinclude three transceivers, e.g., one for each sector of the cell. In anembodiment, the base station 914 a may employ multiple-input multipleoutput (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 914 a, 914 b may communicate with one or more of theWTRUs 902 a, 902 b, 902 c, 902 d over an air interface 915/916/917,which may be any suitable wireless communication link (e.g., radiofrequency (RF), microwave, infrared (IR), ultraviolet (UV), visiblelight, etc.). The air interface 915/916/917 may be established using anysuitable radio access technology (RAT).

More specifically, as noted above, the communications system 900 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 914 a in the RAN 903/904/905 and the WTRUs 902a, 902 b, 902 c may implement a radio technology such as UniversalMobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA),which may establish the air interface 915/916/917 using wideband CDMA(WCDMA). WCDMA may include communication protocols such as High-SpeedPacket Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may includeHigh-Speed Downlink Packet Access (HSDPA) and/or High-Speed UplinkPacket Access (HSUPA).

In an embodiment, the base station 914 a and the WTRUs 902 a, 902 b, 902c may implement a radio technology such as Evolved UMTS TerrestrialRadio Access (E-UTRA), which may establish the air interface 915/916/917using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In an embodiment, the base station 914 a and the WTRUs 902 a, 902 b, 902c may implement radio technologies such as IEEE 802.16 (e.g., WorldwideInteroperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×.CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95(IS-95). Interim Standard 856 (IS-856), Global System for Mobilecommunications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSMEDGE (GERAN), and the like.

The base station 914 b in FIG. 9A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 914 b and the WTRUs 902 c, 902 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In an embodiment, the base station 914 b andthe WTRUs 902 c, 902 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yet anembodiment, the base station 914 b and the WTRUs 902 c, 902 d mayutilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A,etc.) to establish a picocell or femtocell. As shown in FIG. 9A, thebase station 914 b may have a direct connection to the Internet 910.Thus, the base station 914 b may not be required to access the Internet910 via the core network 906/907/909.

The RAN 903/904/905 may be in communication with the core network906/907/909, which may be any type of network configured to providevoice, data, applications, and/or voice over internet protocol (VoIP)services to one or more of the WTRUs 902 a, 902 b, 902 c, 902 d. Forexample, the core network 906/907/909 may provide call control, billingservices, mobile location-based services, pre-paid calling, Internetconnectivity, video distribution, etc., and/or perform high-levelsecurity functions, such as user authentication. Although not shown inFIG. 9A, it will be appreciated that the RAN 903/904/905 and/or the corenetwork 906/907/909 may be in direct or indirect communication withother RANs that employ the same RAT as the RAN 903/904/905 or adifferent RAT. For example, in addition to being connected to the RAN903/904/905, which may be utilizing an E-UTRA radio technology, the corenetwork 906/907/909 may also be in communication with a RAN (not shown)employing a GSM radio technology.

The core network 906/907/909 may also serve as a gateway for the WTRUs902 a, 902 b, 902 c, 902 d to access the PSTN 908, the Internet 910,and/or other networks 912. The PSTN 908 may include circuit-switchedtelephone networks that provide plain old telephone service (POTS). TheInternet 910 may include a global system of interconnected computernetworks and devices that use common communication protocols, such asthe transmission control protocol (TCP), user datagram protocol (UDP)and the internet protocol (IP) in the TCP/IP internet protocol suite.The networks 912 may include wired or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 912 may include a core network connected to one or more RANs,which may employ the same RAT as the RAN 903/904/905 or a different RAT.

Some or all of the WTRUs 902 a, 902 b, 902 c, 902 d in thecommunications system 900 may include multi-mode capabilities, e.g., theWTRUs 902 a, 902 b, 902 c, 902 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 902 c shown in FIG. 9A may be configured tocommunicate with the base station 914 a, which may employ acellular-based radio technology, and with the base station 914 b, whichmay employ an IEEE 802 radio technology.

FIG. 9B is a system diagram of an example WTRU 902. As shown in FIG. 9B,the WTRU 902 may include a processor 918, a transceiver 920, atransmit/receive element 922, a speaker/microphone 924, a keypad 926, adisplay/touchpad 928, non-removable memory 930, removable memory 932, apower source 934, a global positioning system (GPS) chipset 936, andother peripherals 938. It will be appreciated that the WTRU 902 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment. Also, embodiments contemplate that thebase stations 914 a and 914 b, and/or the nodes that base stations 914 aand 914 b may represent, such as but not limited to transceiver station(BTS), a Node-B, a site controller, an access point (AP), a home node-B,an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a homeevolved node-B gateway, and proxy nodes, among others, may include someor all of the elements depicted in FIG. 9B and described herein.

The processor 918 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs). Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 918 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 902 to operate in a wirelessenvironment. The processor 918 may be coupled to the transceiver 920,which may be coupled to the transmit/receive element 922. While FIG. 9Bdepicts the processor 918 and the transceiver 920 as separatecomponents, it will be appreciated that the processor 918 and thetransceiver 920 may be integrated together in an electronic package orchip.

The transmit/receive element 922 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 914a) over the air interface 915/916/917. For example, in one embodiment,the transmit/receive element 922 may be an antenna configured totransmit and/or receive RF signals. In an embodiment, thetransmit/receive element 922 may be an emitter/detector configured totransmit and/or receive IR, UV, or visible light signals, for example.In yet anembodiment, the transmit/receive element 922 may be configuredto transmit and receive both RF and light signals. It will beappreciated that the transmit/receive element 922 may be configured totransmit and/or receive any combination of wireless signals.

In addition, although the transmit/receive element 922 is depicted inFIG. 9B as a single element, the WTRU 902 may include any number oftransmit/receive elements 922. More specifically, the WTRU 902 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 902 mayinclude two or more transmit/receive elements 922 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 915/916/917.

The transceiver 920 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 922 and to demodulatethe signals that are received by the transmit/receive element 922. Asnoted above, the WTRU 902 may have multi-mode capabilities. Thus, thetransceiver 920 may include multiple transceivers for enabling the WTRU902 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 918 of the WTRU 902 may be coupled to, and may receiveuser input data from, the speaker/microphone 924, the keypad 926, and/orthe display/touchpad 928 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor918 may also output user data to the speaker/microphone 924, the keypad926, and/or the display/touchpad 928. In addition, the processor 918 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 930 and/or the removable memory 932.The non-removable memory 930 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 932 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In an embodiment, the processor 918 may access informationfrom, and store data in, memory that is not physically located on theWTRU 902, such as on a server or a home computer (not shown).

The processor 918 may receive power from the power source 934, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 902. The power source 934 may be any suitabledevice for powering the WTRU 902. For example, the power source 934 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 918 may also be coupled to the GPS chipset 936, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 902. In additionto, or in lieu of, the information from the GPS chipset 936, the WTRU902 may receive location information over the air interface 915/916/917from a base station (e.g., base stations 914 a, 914 b) and/or determineits location based on the timing of the signals being received from twoor more nearby base stations. It will be appreciated that the WTRU 902may acquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 918 may further be coupled to other peripherals 938, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 938 may include anaccelerometer, an c-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 9C is a system diagram of the RAN 903 and the core network 906according to an embodiment. As noted above, the RAN 903 may employ aUTRA radio technology to communicate with the WTRUs 902 a, 902 b, 902 cover the air interface 915. The RAN 903 may also be in communicationwith the core network 906. As shown in FIG. 9C, the RAN 903 may includeNode-Bs 940 a, 940 b, 940 c, which may each include one or moretransceivers for communicating with the WTRUs 902 a, 902 b, 902 c overthe air interface 915. The Node-Bs 940 a, 940 b, 940 c may each beassociated with a particular cell (not shown) within the RAN 903. TheRAN 903 may also include RNCs 942 a, 942 b. It will be appreciated thatthe RAN 903 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 9C, the Node-Bs 940 a, 940 b may be in communicationwith the RNC 942 a. Additionally, the Node-B 940 c may be incommunication with the RNC 942 b. The Node-Bs 940 a, 940 b, 940 c maycommunicate with the respective RNCs 942 a, 942 b via an Iub interface.The RNCs 942 a, 942 b may be in communication with one another via anIur interface. Each of the RNCs 942 a, 942 b may be configured tocontrol the respective Node-Bs 940 a, 940 b, 940 c to which it isconnected. In addition, each of the RNCs 942 a, 942 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macro diversity, security functions, data encryption, and thelike.

The core network 906 shown in FIG. 9C may include a media gateway (MGW)944, a mobile switching center (MSC) 946, a serving GPRS support node(SGSN) 948, and/or a gateway GPRS support node (GGSN) 950. While each ofthe foregoing elements are depicted as part of the core network 906, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 942 a in the RAN 903 may be connected to the MSC 946 in the corenetwork 906 via an IuCS interface. The MSC 946 may be connected to theMGW 944. The MSC 946 and the MGW 944 may provide the WTRUs 902 a, 902 b,902 c with access to circuit-switched networks, such as the PSTN 908, tofacilitate communications between the WTRUs 902 a. 902 b, 902 c andtraditional land-line communications devices.

The RNC 942 a in the RAN 903 may also be connected to the SGSN 948 inthe core network 906 via an IuPS interface. The SGSN 948 may beconnected to the GGSN 950. The SGSN 948 and the GGSN 950 may provide theWTRUs 902 a, 902 b, 902 c with access to packet-switched networks, suchas the Internet 910, to facilitate communications between and the WTRUs902 a, 902 b, 902 c and IP-enabled devices.

As noted above, the core network 906 may also be connected to thenetworks 912, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 9D is a system diagram of the RAN 904 and the core network 907according to an embodiment. As noted above, the RAN 904 may employ anE-UTRA radio technology to communicate with the WTRUs 902 a, 902 b, 902c over the air interface 916. The RAN 904 may also be in communicationwith the core network 907.

The RAN 904 may include eNode-Bs 960 a, 960 b, 960 c, though it will beappreciated that the RAN 904 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 960 a, 960 b, 960c may each include one or more transceivers for communicating with theWTRUs 902 a, 902 b, 902 c over the air interface 916. In one embodiment,the eNode-Bs 960 a. 960 b, 960 c may implement MIMO technology. Thus,the eNode-B 960 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 902 a.

Each of the eNode-Bs 960 a. 960 b, 960 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 9D, theeNode-Bs 960 a, 960 b, 960 c may communicate with one another over an X2interface.

The core network 907 shown in FIG. 9D may include a mobility managementgateway (MME) 962, a serving gateway 964, and a packet data network(PDN) gateway 966. While each of the foregoing elements are depicted aspart of the core network 907, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 962 may be connected to each of the eNode-Bs 960 a, 960 b, 960 cin the RAN 904 via an S1 interface and may serve as a control node. Forexample, the MME 962 may be responsible for authenticating users of theWTRUs 902 a, 902 b, 902 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 902 a,902 b, 902 c, and the like. The MME 962 may also provide a control planefunction for switching between the RAN 904 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 964 may be connected to each of the eNode-Bs 960 a,960 b, 960 c in the RAN 904 via the S1 interface. The serving gateway964 may generally route and forward user data packets to/from the WTRUs902 a, 902 b, 902 c. The serving gateway 964 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 902 a,902 b, 902 c, managing and storing contexts of the WTRUs 902 a, 902 b,902 c, and the like.

The serving gateway 964 may also be connected to the PDN gateway 966,which may provide the WTRUs 902 a, 902 b, 902 c with access topacket-switched networks, such as the Internet 910, to facilitatecommunications between the WTRUs 902 a, 902 b, 902 c and IP-enableddevices.

The core network 907 may facilitate communications with other networks.For example, the core network 907 may provide the WTRUs 902 a, 902 b,902 c with access to circuit-switched networks, such as the PSTN 908, tofacilitate communications between the WTRUs 902 a, 902 b, 902 c andtraditional land-line communications devices. For example, the corenetwork 907 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 907 and the PSTN 908. In addition, the corenetwork 907 may provide the WTRUs 902 a, 902 b. 902 c with access to thenetworks 912, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 9E is a system diagram of the RAN 905 and the core network 909according to an embodiment. The RAN 905 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 902 a, 902 b, 902 c over the air interface 917. As will be furtherdiscussed below, the communication links between the differentfunctional entities of the WTRUs 902 a, 902 b, 902 c, the RAN 905, andthe core network 909 may be defined as reference points.

As shown in FIG. 9E, the RAN 905 may include base stations 980 a, 980 b,980 c, and an ASN gateway 982, though it will be appreciated that theRAN 905 may include any number of base stations and ASN gateways whileremaining consistent with an embodiment. The base stations 980 a, 980 b.980 c may each be associated with a particular cell (not shown) in theRAN 905 and may each include one or more transceivers for communicatingwith the WTRUs 902 a, 902 b, 902 c over the air interface 917. In oneembodiment, the base stations 980 a, 980 b. 980 c may implement MIMOtechnology. Thus, the base station 980 a, for example, may use multipleantennas to transmit wireless signals to, and receive wireless signalsfrom, the WTRU 902 a. The base stations 980 a, 980 b, 980 c may alsoprovide mobility management functions, such as handoff triggering,tunnel establishment, radio resource management, traffic classification,quality of service (QoS) policy enforcement, and the like. The ASNgateway 982 may serve as a traffic aggregation point and may beresponsible for paging, caching of subscriber profiles, routing to thecore network 909, and the like.

The air interface 917 between the WTRUs 902 a, 902 b. 902 c and the RAN905 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 902 a, 902 b, 902 cmay establish a logical interface (not shown) with the core network 909.The logical interface between the WTRUs 902 a. 902 b, 902 c and the corenetwork 909 may be defined as an R2 reference point, which may be usedfor authentication, authorization, IP host configuration management,and/or mobility management.

The communication link between each of the base stations 980 a, 980 b,980 c may be defined as an R8 reference point that includes protocolsfor facilitating WTRU handovers and the transfer of data between basestations. The communication link between the base stations 980 a, 980 b,980 c and the ASN gateway 982 may be defined as an R6 reference point.The R6 reference point may include protocols for facilitating mobilitymanagement based on mobility events associated with each of the WTRUs902 a, 902 b, 902 c.

As shown in FIG. 9E, the RAN 905 may be connected to the core network909. The communication link between the RAN 905 and the core network 909may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 909 may include a mobile IP home agent(MIP-HA) 984, an authentication, authorization, accounting (AAA) server986, and a gateway 988. While each of the foregoing elements aredepicted as part of the core network 909, it will be appreciated thatany one of these elements may be owned and/or operated by an entityother than the core network operator.

The MIP-HA may be responsible for IP address management, and may enablethe WTRUs 902 a, 902 b, 902 c to roam between different ASNs and/ordifferent core networks. The MIP-HA 984 may provide the WTRUs 902 a, 902b, 902 c with access to packet-switched networks, such as the Internet910, to facilitate communications between the WTRUs 902 a, 902 b, 902 cand IP-enabled devices. The AAA server 986 may be responsible for userauthentication and for supporting user services. The gateway 988 mayfacilitate interworking with other networks. For example, the gateway988 may provide the WTRUs 902 a, 902 b, 902 c with access tocircuit-switched networks, such as the PSTN 908, to facilitatecommunications between the WTRUs 902 a, 902 b, 902 c and traditionalland-line communications devices. In addition, the gateway 988 mayprovide the WTRUs 902 a, 902 b, 902 c with access to the networks 912,which may include other wired or wireless networks that are owned and/oroperated by other service providers.

Although not shown in FIG. 9E, it will be appreciated that the RAN 905may be connected to other ASNs and the core network 909 may be connectedto other core networks. The communication link between the RAN 905 theother ASNs may be defined as an R4 reference point, which may includeprotocols for coordinating the mobility of the WTRUs 902 a. 902 b, 902 cbetween the RAN 905 and the other ASNs. The communication link betweenthe core network 909 and the other core networks may be defined as an R5reference, which may include protocols for facilitating interworkingbetween home core networks and visited core networks.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element may be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, optical media such as CD-ROM disks, anddigital versatile disks (DVDs). A processor in association with softwaremay be used to implement a radio frequency transceiver for use in aWTRU, WTRU, terminal, base station, RNC, or any host computer.

1-24. (canceled)
 25. A multiband device, comprising: a processorconfigured to: send a request via a first frequency band, wherein therequest is associated with a second frequency band, and wherein therequest indicates an allocation start time and a duration; receive amultiband Clear to Send (MCTS) frame via the first frequency bandaccepting the request; and send a beamforming signal associated with therequest.
 26. The multiband device of claim 25, wherein the requestcomprises a multiband Request to Send (MRTS) frame.
 27. The multibanddevice of claim 25, wherein the beamforming signal is sent via thesecond frequency band.
 28. The multiband device of claim 25, wherein theprocessor is further configured to: receive a beamforming trainingschedule.
 29. The multiband device of claim 28, wherein the beamformingtraining schedule is received via an Access Point (AP).
 30. Themultiband device of claim 28, wherein the beamforming signal is abeamforming training signal that is part of a beamforming transmissionthat comprises a plurality of beamforming training signals.
 31. Themultiband device of claim 25, wherein the MCTS frame comprises a fieldthat indicates whether the request is accepted.
 32. The multiband deviceof claim 25, wherein the beamforming signal comprises a sector sweep(SSW) frame.
 33. The multiband device of claim 33, wherein the SSW framedoes not comprise a media access control (MAC) body.
 34. The multibanddevice of claim 25, wherein the first frequency band is associated witha quasi-omni transmission and the second frequency band is associatedwith a directional transmission.
 35. The multiband device of claim 25,wherein the first frequency band is a 5 GHz band and the secondfrequency band is a 60 GHz band.
 36. A method comprising: sending arequest via a first frequency band, wherein the request is associatedwith a second frequency band, and wherein the request indicates anallocation start time and a duration; receiving a multiband Clear toSend (MCTS) frame via the first frequency band accepting the request;and sending a beamforming signal associated with the request.
 37. Themethod of claim 36, wherein the request comprises a multiband Request toSend (MRTS) frame.
 38. The method of claim 36, wherein the beamformingsignal is sent via the second frequency band.
 39. The method of claim36, further comprising: receiving a beamforming training schedule. 40.The method of claim 39, wherein the beamforming training schedule isreceived via an Access Point (AP).
 41. The method of claim 39, whereinthe beamforming signal is a beamforming training signal that is part ofa beamforming transmission that comprises a plurality of beamformingtraining signals.
 42. The method of claim 36, wherein the MCTS framecomprises a field that indicates whether the request is accepted. 43.The method of claim 36, wherein the beamforming signal comprises asector sweep (SSW) frame.
 44. The method of claim 43, wherein the SSWframe does not comprise a media access control (MAC) body.
 45. Themethod of claim 36, wherein the first frequency band is associated witha quasi-omni transmission and the second frequency band is associatedwith a directional transmission.
 46. The method of claim 36, wherein thefirst frequency band is a 5 GHz band and the second frequency band is a60 GHz band.